Progressive Web App Compatibility Test

Introduction

This article is part of Browser Compatibility Test. Open the compatibility test tool to run WebGL, WebGPU, codec, and API probes in your current browser.

A progressive web app compatibility test validates Service Worker support, offline storage, installability signals, push notifications, and background sync availability.

Overview

Progressive web app compatibility testing validates the API cluster PWAs depend on: Service Workers for caching and offline support, storage APIs for persistence, installability prerequisites, and optional push notifications and background sync features.

A progressive web app compatibility test validates Service Worker support, offline storage, installability signals, push notifications, and background sync availability.

PWAs require multiple APIs to pass together. Service Worker alone is insufficient if persistent storage or secure context checks fail.

Mobile browsers and desktop browsers differ on installability cues and notification permission flows.

Progressive web apps are not a single API. They are a cluster of Service Worker, storage, installability, and notification capabilities that must work together for offline modes and install prompts to feel reliable.

API probes from the web API compatibility test cover many primitives PWAs need, but PWA-specific validation also checks how those APIs combine in real install and offline flows.

• ●Service Worker registration and API availability probes
• ●Offline support via Cache API and IndexedDB validation
• ●Installability and manifest-related platform signals
• ●Push notifications and background sync feature detection

Service Workers, Offline Support, and Installability

Service Worker registration requires secure contexts and compatible storage behavior. Failing IndexedDB or Cache API probes often predicts broken offline sync even when serviceWorker exists on navigator.

Installability signals differ between Chromium, Firefox, and Safari. Probe the APIs your install UX actually calls instead of assuming beforeinstallprompt everywhere.

If you are building a broader compatibility practice, anchor PWA checks inside the framework described in what a browser compatibility test is so graphics and codec requirements stay visible alongside PWA APIs.

Key Formula

Gate install prompts behind probes for Service Worker, secure context, and minimum storage API support.

Treat notification and background sync as optional tiers. Core offline functionality should not depend on them.

Treat push notifications and background sync as optional tiers. Core offline reading or cart functionality should not depend on notification permission flows.

• ●Use consistent probe definitions across browsers
• ●Combine scores with qualitative failure notes
• ●Re-run after browser or driver updates

Step by Step

Apply these steps in order so compatibility results stay comparable across browsers and releases.

1. 1

   Probe Service Worker API

   Confirm serviceWorker in navigator and secure context before offering offline modes.

2. 2

   Validate storage APIs

   Check Cache API, IndexedDB, and persistent storage availability for offline data.

3. 3

   Assess installability signals

   Verify beforeinstallprompt or platform-specific install paths where applicable.

4. 4

   Check notification APIs

   Probe PushManager and Notification permission state separately from API presence.

5. 5

   Define PWA fallback UX

   Show bookmark or add-to-home-screen guidance when full PWA features are unavailable.

Practical Examples

A productivity app checks Service Worker and IndexedDB at login. Failing browsers get an online-only mode with clear messaging instead of broken offline sync.

A retailer gates push notification signup behind Notification API probes. Users on unsupported browsers still complete purchases without notification prompts blocking checkout.

A productivity app checks Service Worker and IndexedDB at login. Failing browsers get an online-only mode with clear messaging instead of broken background sync.

A retailer gates push signup behind Notification API probes. Users on unsupported browsers still checkout without notification prompts blocking the purchase flow.

• ●Save probe JSON with each support ticket
• ●Map failures to visible fallbacks
• ●Review examples in sprint retrospectives

FAQ

FAQDoes passing PWA probes guarantee install prompts?

No. Browsers apply engagement heuristics and platform rules beyond API availability.

FAQWhy do Service Workers fail on HTTP?

Service Workers require a secure context. Use HTTPS in staging and production for accurate probes.

FAQAre PWAs supported on iOS Safari?

Support has improved but differs from Chromium. Run probes on real iOS devices for accurate capability data.

FAQWhich APIs are essential for offline mode?

At minimum, Service Worker plus a storage API such as Cache API or IndexedDB on a secure origin.

FAQShould install buttons hide when probes fail?

Yes. Show bookmark or add-to-home-screen guidance instead of broken install flows.